A well-known technique for constructing inexpensive linear motion axes utilizes precision ground steel shafts—each fixed at both ends—upon which a carriage slides. An example of such a stage, constructed in accordance with the present invention, is shown in FIG. 3. Crucial to the proper function of this mechanism are the parallelism of both shafts and the precise alignment of guide bearings upon which the carriage slides on the precision shafts. Should the distance between the shafts vary, or if the distance between the shafts does not perfectly match that between the guide bearings, binding will occur. Achieving this precise alignment typically requires high precision machining of multiple different components.
In addition, one of the key challenges facing machine tool designers is to create rigid machine frames which resist tool deflection and which are also damped sufficiently to suppress vibrations. Another challenge is to create precision alignment both between the bearing elements comprising each axis, and between the various axes comprising a machine. For example, a standard 3-axis milling machine consists of X, Y, and Z axes which in the ideal case are perfectly orthogonal to each other. Traditional machine construction techniques rely on bulky castings, forgings, or extrusions to achieve stiffness and damping, and precision machining of components to achieve alignment within and between motion axes. These factors contribute to the cost of fabricating machine tools, and make it difficult to produce machine tools for the mass consumer market.